This invention relates to a hydraulic brake for vehicles. The invention particularly relates to a hydraulic differential brake for vehicles with an antiskid system.
West German Reference No. 32 12 359 teaches a hydraulic brake device for vehicles which comprises a hydraulic system consisting of a pump with a reservoir for the hydraulic fluid and a non-return valve for the braking. The mechanical or kinetic energy produced by the engine is converted into thermal energy in the hydraulic fluid.
However, this system is for installation in a new vehicle and is unsuitable as a replacement for conventional brakes. A control of the braking force in accordance with the necessary conditions is not possible.
The main disadvantages of conventional brakes reside in the fact that the brake wears and that is damaging to the environment. Practically all brake linings contain asbestos fibers which are rubbed off during the braking procedure and released into the environment. For this reason the wear of current vehicle brakes contributes heavily to the contamination of the environment with very fine asbestos particles and with heavy metals originating from the discs and drums of the brakes. Moreover, the expense occasioned over the service life of a vehicle by brake wear is considerable.
An antiskid system is also known which is intended to electronically prevent the wheels from skidding during braking, whereby the brake shoes are loosened again somewhat during the braking procedure shortly before the wheel stops in order to keep the wheel turning against the forces of friction. The known antiskid system has a set closing and opening frequency of approximately 10 Hz, which is noticeable in the form of an unpleasant chattering. In addition, this antiskid system requires a considerable expenditure of the electronic and electro-magnetic-hydraulic components, thus making it expensive and, for this reason, suitable for only a small number of vehicles. Aside from the above, this system is very susceptible to failure due to its complexity.